P0403EGR A Control Circuit/Open
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Needs a drive cycle to confirm a fix
- How the car detects it
- Exhaust gas recirculation (EGR) routes part of the exhaust back into the intake to lower combustion temperature and NOx. P0403 concerns the electrical drive of the EGR valve – solenoid, stepper motor, DC motor or vacuum regulator. The module checks the output and sets the code for an open circuit (GM: above 200 kΩ, MIL after two trips; Ford after 4 s, MIL after two trips). Newer systems report shorts separately as P0489 (low) and P0490 (high); Ford and older GM systems include them in P0403. EGR is then switched off for the rest of the trip.
- What you may notice
- Check engine light on
- EGR switched off: pinging (petrol) or higher NOx
- Usually no loss of power
- Likely causes
- LikelyConnector at the EGR valve corroded or loose
- PossibleBroken control or supply wire
- PossibleCoil or motor in the EGR valve burnt out
- RareDriver in the engine module
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Easy · Often possible to do yourself.Typical cost: €30 – €600
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.